Chapter 1 - Pitot-Static Systems Flashcards
What is static pressure?
Force that stationary air exerts equally in all directions
Why do we have a pair of static ports?
Reduces the effect of dynamic pressure.
Does an unpressurised AC have a higher or low static pressure inside the AC?
Lower inside
What instruments does static pressure feed into?
Altimeter, VSI, Airspeed, Machmeter
Dynamic pressure feeds into what instruments?
ASI, Machmeter
Detail the Pitot-Static Systems errors?
B - Blockages
L - Leaks
I - Instrument
M - Manoeuvre
P - Position
What is instrument error in a instrument?
Instrument errors occur from defects in the manufacturing process and system design. Air can be disturbed by small particles of dust, dirt and moisture. Insects are also a problem as tubes make ideal nesting
areas. Errors can be mitigated by calibration, covers, drains, alternate sources and pre-flight checks.
What is Manoeuvre error?
More/less airflow over an aircraft
What is Position error?
Position of Pitot on the AC, different pressures, creating errors.
What is blockage error?
Caused by ice, grit or insects. Can be partial or total.
What is PUD-SOD?
With a blockage - PITOT will UNDERREAD in DESCENT. Overread in climb.
STATIC will OVERREAD in DESCENT. Under read in climb.
What is a leak error?
Fractures in the light alloy piping can occur either within or outside a pressurised area. If the former, may go undetected. Although systems can leak to varying degrees, we assume that the leak is significant.
With an increase in airspeed what happens to static pressure?
It decreases
